BD3870FS-E2 Rohm Semiconductor, BD3870FS-E2 Datasheet - Page 10

• Manufacturer Part Number: BD3870FS-E2
• Description: IC SOUND PROCESSOR SSOP-A24
• Manufacturer: Rohm Semiconductor
• Series: -r
• Type: Audio Processorr

Specifications of BD3870FS-E2

• Applications: Audio Systems
• Mounting Type: Surface Mount
• Package / Case: 24-SOP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

BD3870FS,BD3871FS,BD3872FS,BD3873FS
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www.rohm.com
2) Treble filter
3) Matrix surround
Standard values of R1, R2 (reference)
Matrix surround is constructed as shown above. Gains are defined as follows:
In-phase Gain: Gains obtained on OUT1 and OUT2 against IN1 when inputting a signal of the equivalent level and
in-phase (L=R) to IN1 and IN2.
Single-phase Gain: Gains obtained on OUT1 and OUT2 against IN1 when inputting a signal to IN1 and AC-grounding IN2
(R=0).
Opposite-phase Gain: Gains obtained on OUT1 and OUT2 against IN1 when inputting signals of the equivalent level and
opposite-phase (L-R) to IN1 and IN2.
* The actual boost cut amount may deviate from the standard values in some degree.
Treble Boost Cut Amount
14dB (BD3872FS only)
OUT1
OUT2
OUT1
OUT1
IN1
IN1
IN1
IN1




10dB
12dB
0dB
2dB
4dB
6dB
8dB
4.14

OUT2
OUT2
IN2
2
IN2
2.14
2
L
IN

L

L







L
4.14
4.14
Fig.7
2

2,07
2

L
1.07
R
L
R2
L

C
+
-
IN1
IN2

2.14
Resistance (kΩ) * Typ.
R1
2.14
13.39
18.10
21.84
24.81
27.20
29.04
2
7.46
R1
× 1/2
× 1/2
2
0
L



L
OUT



L
+
+

-
L

3.14
20log
20log2.07
1
36.28
28.82
22.89
18.18
14.44
11.47
9.08
7.24
R2
× 2.14
Fig.9

10/15
1.07

20log3.14
6.3

+
0.59
+
+
+
-
+
20log1
(dB)
(dB)
(4.14L/2 - 2.14R/2)
(4.14R/2 - 2.14L/2)
10
fc =
G (boost) = 20log
G (cut) = 20log
Zc =
OUT2
(dB)
0
OUT1
2πR2C
jωc
1
1
G
(dB)
3dB
3dB
(Ω)
R1+R2+Zc
(Hz)
R2+Zc
R1+R2+Zc
R2+Zc
Fig.8
fc
(dB)
Technical Note
2010.10 - Rev.A
(dB)
G
G
f